Ocean Reanalysis Products

Synthesis/Analysis: Ocean Data Assimilation SystemOur 4D-VAR data assimilation system is developed by the MEXT K-7 project. The Ocean General Circulation Model is version 3 of the GFDL Modular Ocean Model (MOM3), which isequipped with several sophisticated schemes; e.g., the nonlocal K Profile Parameterization (KPP) for mixed layer physics, the Gent and McWilliams (GM) scheme for isopycnal mixing, andquicker advection scheme. The horizontal resolution is 1o in both latitude and longitude, with 36 vertical levels spaced from 10 m near the sea surface to 400 m at the bottom. This model is better able to reproduce ocean circulation processes and is expected to form a platform suitable for the use of the 4D-VAR adjoint model.The assimilated elements in this study are temperature and salinity from the World OceanDatabase 2001 (WOD01), Fleet Numerical Meteorology and Oceanography Center (FNMOC)dataset, Reynolds SST, OISST values, and Argo float data from the Coriolis Data Center, andsea-surface dynamic-height anomaly data derived from TOPEX/Poseidon altimetry. In addition, the climatologies of the World Ocean Database 1998 (WOD98) were used as background data for regions without observational coverage. All observational data were averaged onto 1o by 1o bins and then compiled as series of 10-day means for the surface data and monthly means for the subsurface data. The assimilation window is 16 years during 1991-2006.